Stereoscope



Aug. l0, 1943, G. M. MAST 2,326,718

STEREOSCOPE Filed Jan. '7, 1941 2 Sheets-Sheet 1 nventar' GIFFORD M. MAST E M Cttorneg Aug. 1G, 1943. G. MMAST 2,326,718

STEREOSCOPE Filed Jan. '7, 1941 y2 sheets-sheet 2 CIIIIEIUEIDCIEIEIEIDDDEIEIEIEIEIDEIDDD 47 INVENTOR.

GIFFOB 'MMASI BY waz/52M M ATTORNEY.

Patented Aug. l0, 1943 UNITED STATES PATENT oFFlcE STEREOSCOPE Gilford M. Mast, Davenport, Iowa, assigner to 11 Claims.

My invention has reference to a stereoscope, and is of that type which is used with a strip of picture film bearing pairs of stereoscopic pictures for simultaneous viewing through the optical channels of the instrument. Machines of this type have been quite generally distributed commercially under the name of Tru-Vue. They are designed with a mechanism for advancing the strip of picture lm in a step-bystep movement through the machine.

One of the chief purposes of the present invention is to simplify the device in such a manner as to reduce manufacturing costs. This is accomplished not only by reducing the number of parts one third below the number previously employed, but by simplifying the assembly of the parts so that no screws, rivets, or welding operations need be made use of as in previous forms of the device. This is done by a snapping and friction locking in the assemblage of the parts, which will be herein more fully set forth.

The snapping together of the parts is made pos' sible by the use of commercial plastic in the construction of the casing, which is a streamlined efect, and molded into the desired form, with a main body portion and closure part therefor.

Another feature of the invention is a unitary sliding member, carrying the devices for engaging with a strip of lm used in combination with the stereoscopic viewer. over previous devices, this sliding member does not enter or cross the optical channels of the instrument.

Another feature of the invention is a specially designed seat in the casing for the holding of translucent diffusing windows which are used. These seats, which provide results which are usually accomplished either by an undercut in the molding, or a separate part, is usually molded in a single part by standard methods. It allows the translucent windows, which may be made of some such material as celluloid, to be sprung into position from the outside of the casing, but prevents their removal from the outside in any normal use.

The strip of lm made use of in combination with this viewer is of special design, being provided along one edge with perforations which allow its exposure and processing with the aid of standard 35 mm. motion picture equipment, while being provided at theother edge with engaging means at regular intervals, corresponding to the length of movement of the film at each advance thereof when used in the viewer. This 55 As an improvement perforations, instead of gliding along-the surface of the lm; second, it results in a pair of corre-l sponding pictures being brought into line before the translucent viewing windows each time that the mechanism is advanced to its stop, and regardless of the previous position of the film in the viewer. Thus it results in what may be termed automatic framing. 1

The above named, and other features and advantages of the invention will more fully appear from the following specification, reference being had to the accompanying drawings, in which:

Fig. 1 is a perspective view of an instrument embodying the invention, with a roll of picture lm in position for use.

Fig. 2 is an end view thereof in the position in which it is generally held when in use.

Fig. 3 shows the closure section of the casing removed from the body portion.

Fig. 4 shows the body portion of the casing,

separated from the closure part, and with a portion broken away.

Fig. 5 is a cross-section on the broken line 5 5 of Fig. 3.

Fig. 6 is a cross-section on the line 6--6 of Fig. 4.

Fig. '7 is an enlarged view of the slide unit, in perspective, with one corner broken away.

Fig. 8 show-'the pawl member, detached, in perspective.

Fig. 9 is a detail of the pawl retaining spring.

Fig. 10 is a detail of the slide knob, broken apart.

Fig. 11 is a side view of the slide unit, partly broken away, with the pawl mechanism disclosed.

the translucent windows.

Fig. 14 is a cross-section on the line I4-Ifl of Fig. 13.

Fig. 15 is a plan View of a blank from which the slide member is produced.

In all of the structural figures except Figs. 1

and 2 the parts are shown which they are assembled. l

The casing of the viewer instrument consists of two molded parts, a body portion (designated generally by the -reference letter A) and `a lid in the positions in cent diffusing window 38 may be sprung.

or closure portion (indicated generally by the letter B), which portions are shown united in Figs. 1 and 2; In Figs. 3 and 4, and 5 and 6 said parts'are shown separated but in thesame orientation as when united. The-body -portion consists of a pair of eye-tubes I0, with the interocu- 2,326,71va e l f' the mold while the groove on the outside of the'` strip 34 is formed by a raised rib on the punch of the mold. A very thin film of the plastic mate- Y rial is left between them, and Ithis may be readily lar spacing customary for binocular instruments, Y

united by a bridge l5. The casing is of hollow formation, molded of commercial plastic or other suitable material. It bifurcates into two relatively thin-walled spaces, comprising the eyetubes referred to. In the small end of each of said eye-tubes is a plate II, provided with an oval opening I2, and on the inner side of each of the plates I I over the opening- I 2 is a lens I, held inplace by guides I3 and I in the eyetubes, and further secured from release by clips 5, provided with openings in line with the openings I2. The clips 5 areof spring material, and are held in place by points 6 which engage the guides I4 yieldably.

Projected beyond the sides of the eye-tubes are flanges 20 and 2l, with upwardly curved ends as shown at 22in Fig. 4. The lower sides of said ilanges are ribbed as an ornamental treatment, which serves to disguise the line I8 along which the lid and body portion'of the casing join.

The largeend of the body portion A is open, and is closed for use by the lid B, consisting of a base-plate 30 and side plates 3l. The sides 3i the outside of the casing. It is returned to the original position upon being released by a coiled spring B, connected at one end to a lug 21 in the closely engage the anges 30,-and are provided on their inner surfaces with small grooves 32 for engagement with ridges 25 in the faces of said flanges. The platesSl possess suiiicient resiliency to permit of their being snapped in place over the ridges 25, holding the parts A and B together and secure from accidental release.

Projected upward from the flange 2l is a plate 23, accommodated by an opening 32 in the side plate 3i of the lid which is adjacent thereto. The opening remaining between the top of said plate 23 and the bottom of the opening 32 allows the handle 48 of the slide mechanism to project through the casing, and the ends of the open-` ing 32 act as stops to'lirnit its motion'in each direction. A

The base-plate is provided with a pair of spaced openings 33, in register with the openings I2 of the eye-tubes, .and outlined at their side edges by strips 33a. These strips, which are integral with the base-plate, form film guides in connection with ledges 35 spaced therefrom and parallel therewith. These lm guides support and conduct the lm 3 in its passage through the viewer, between the lid and body portions B and A, the film being held in slidable relation with said guides by the edges of the side plates of the body at 26, (Fig. 6),which are spaced a little ways from the guides 3d when the body and lid parts are united. Slight bumps in the guides and in the side plates 26 oier suitable resistance to the passage of the lm to prevent accidental slipping thereof. v

vThe strips 33 and ledges 35 (Figs. 13 and 14) cooperate to form a seat into which the translu- As may be seen from the drawings, the window 38 may be readily inserted through the opening 33 by springing the same exibly into an arch shape.- Once in position in the seat it rests against the strips 34 and ledges 35 so that it is well supported from pressure from the outside of the casing (uppermost in the figures). This seat for the window may be readily molded because the opening 33 is formed by a peg in the cavity of casing, 'and at the other end to a post 48 at the end of the slide member (Fig. 11).

In Figs. 7, 8, 9, and lll the parts of the slider mechanism are shown in exploded positions, with an assembly thereof disclosed by the broken out section in Fig. 11. The case of the slider is formed from a single blank of metal as shown in Fig. 15, after a cutting and punching operation. 'I'he handle 48 projects through the casing and carries a knob l0, which is'held on the handle by a friction lock, and by engagement with vrecesses 49 in the handle. Grooves 'II in the knob engage these catches,`and while the knob can be readily slipped into position, its accidental release is prevented. f

The movable fllm engaging tooth 5I projects through the opening 43 in the slider case, and is part of a pawl unit, shown in Fig. 8. The pawl is held from lateral movement by the' side walls of the case, and is held in yieldable contact with a notch El in the spring 60, and holds thg pawl from movement longitudinally. The 'arm 54 is projected at an angle into a cam rider or follower 53,v which engages the arcuate edge of a cam 3l' on the inner face of the lid part B of the casing. In the extreme returned position of the slider dll the cam 3l acts to withdraw .the tooth 5I into the case of the slider, with a resultant disen-i gagement of the tooth with the picture lm, permitting such film to be freely withdrawn from the viewer in the reverse direction from that in which it is normally advanced through the instrument. As the slider is again moved in a feed direction the cam and rider 53 disengage and the tooth 5I is' again forced into engaging position by the spring Gil.

The tooth 5i engages withperforations 8l of specially designed picture film shown in Fig. 12. The pictures indicated at 82 are so spaced on the strip of lm that a pair of stereoscopic views will be at such distance apart as to come into register with the eye openings I2 of the viewer. This requires a non-standard frame separation on film of the type used for 35 mm. motion picture work. Such picture lm may, however, be processed on commercial 35 mm. motion picture equipment if it is provided with the standard 35 mm. perforations along one edge, as shown at 8B. Previous devices of this type have used this same perforation along the edge or edges engaged by a toothed feeding mechanism. On account of resulting faults and drawbacks in the use of said standard perforations it was sought to improve thereon by the use of a special type oi' perforation, such as shown at 8|,fwhich perforations always bear the same positional relation to a correlated pair of pictures on the lm. Following the previous usage the pictures of a stereographic pair are separated by -two other pictures, the left one of which is the right eye picture of the pair following normally in sequence with said first-named pair. For each change of pictures the lm is advanced twothirds of the inter-ocular distance, and by spacing the perforatlons 8l to correspond therewith, and placing them in suitable relation to the pictures, as determined by certain dimensions of the viewer, definitely causes a stereoscopic pair of pictures to be brought into register with the eye-holes of the viewer each time that the slider is advanced until the handle 48 comes in contact with the leading edge of the recesses 32 in the lid of the viewer. Should a stereoscopic pair be gotten out of alignment with the eye-tubes by an incomplete operation of the slider, or from other cause, upon the next operation of the slider the tooth will glide along the surface of the film until `it reaches the perforation with which it previously engaged, and will re-engage therewith, advancing the picture film until the stereoscopic pair is brought into proper position for viewing.

While the picture film has been shown herein in the form of a simple strip, capable of being rolled at the ends, it can also be in the form of a loop for continuous operation. This would be of advantage in the operation of a display stereoscope, on a desk or counter, to prevent the strip of film from being removed from the machine, surreptitiously or otherwise.

What I claim, and desire to secure, is:

1. A stereoscope, adapted for use with a strip of picture film, comprising a casing formed of a body portion, including eye-tubes open at one of their ends, lenses in the other ends thereof, a lid removably engageable with the open end of the casing, to form a closure therefor, with a passage between the body portion and lid for the movement of a strip of lm, translucent Windows in said lid in register with the eyetubes, means for guiding a strip of film through said passage, operable from without the casing, and means in said lid for holding said last-named means normally out of engaging position.

2. A stereoscope adapted for use with a strip of picture lm, formed of moldable plastic material, and embracing a hollow body portion with sight channels and open at one of its ends, lenses in the other ends of said sight channels, a lid for the open end provided with parts adapted for a frictional engagement with the body portion, and capable of being snapped into position thereon, with clearance between said body portion and lid for the passage of a strip of film, a slide unit near said clearance passage provided with means for engagement with a strip of film near its edge, to give a feed movement thereto, and means in said lid for holding said last-named means out of engaging position,

3. A film viewing instrument adapted for use with a strip of picture film, comprising a hollow body portion embracing a pair of tapered eyetubes, open at its larger end, a lid engageable with the body portion, lenses in the smaller ends of the eye-tubes, diffusion windows in said lid in registry with the lenses, said body portion and lid being spaced to permit the passage of a strip of picture lm, a slide unit movable adjacent to said space, a film engaging member carried by the lid is attached, a slide said slide unit, including a vpawl and tooth thereon, a cam within said lid engageable with said pawl to release the tooth at the end of a feed movement thereof, means for the movement of the slide unit from without the casing, and spring means for returning said slide unit to its normal position, following a feed movement thereof.

4. A stereoscope, or loop of picture film, comprising a plastic body portion, molded in a single piece, including a pair of tapered eye-tubes open at their larger ends, a lid for the open end formed of plastic material, molded in a single piece, having resilient parts capable of bodyportion, with a space between said parts for the passage of a strip or logp of film, lenses in the small ends of the eye-tubes, translucent diffusing windows in said lid, in register with said eye-tubes, pairs of tracks on the inner face of said lid, at the sides of said windows, with seats at the sides of the windows to receive the ends thereof, capable of being sprung into place from without the lid, and non-removable when unit in said lid carrying means for engagement with a strip of film at its edge, to give a feed movement thereto, and

means for returning said slide unit to its initial position, with said last-named means out of engagement.

5. In a picture film viewing machine, a slide unit formed from a flat thin piece of metal, bendable into U-form in cross-section, provided in one of its sides with an opening for a tooth actuating part, and an opening in its bottom for free movement of a tooth, also having bendable portions at its ends, one of which forms a post for attachment of a spring, and an arm bent laterally to form an actuating piece for the slide unit.

6. A picture film viewing apparatus, comprising a hollow body portion, provided with a pair of eye-tubes, and a lens in one of the ends of each thereof, a closure for the other ends, spaced from the body portion to permit the passage of a strip of film, diffusion windows in said closure, in line with the lenses, a slide unit in said apparatus, provided with a pawl mechanism engageable with perforations in the edge of a strip of -with binocular eye-pieces and central sight passage therefor, open at one end, and a lid forming a closure for said end, and continuing the sight passage, a lm shifting slide unit movable in a space at one side of the body portion, non-interfering with the sight channel, and provided with a lm feeding ratchet mechanism, means in said lid for holding said ratchet mechanism out of operation at the end of a feed movement, and complementary means in said body and lid at the sides of said sight passage, for supporting and guiding a strip of picture film through said device, to be viewed therein.

8. In combination, a device for viewing a series of stereoscopic pictures on a perforated tape, the device having a casing forming binocular eye tubes, and a tape suitably perforated for use with said device, the device having means for receiving and guiding the tape over registering adapted for use with a strip a snap connection with the windows, means operable manually from outside said casing for advancing said tape, by engaging 9. In combination, a devicevfor aligning a series of complementary picture pairs on a; perforated tape over' a pair of registering windows, and a tape with picture pairs suitably disposed thereon and with perforations suitably disposed thereon with relation` to said pictures. means reciprocably operable between definite limiting positions less than four-thirds the separation of I .t the registering windows, to engage said perforations with a claw and advance them in the line of said registering windows, means enabling said claw to release said perforations during its return movement, a tape with pictures disposed on it at intervals one-third the separation of the registering windows, and with perforations for engagement with the aforesaid claw also disposed on it at intervals of two-thirds the separation of the registering windows, and in such relation to said pictures that upon the claw being advanced to its hunting position a complementary pair of pictures registers with said registering windows.

10. A lm viewing device for viewing in the still state a series of pictures or images on a perforated lm tape, the device having a casing forming binocular eye tubes, and extending forward and having teeth over which are sprung,

by means ofl inden'tations therein a front plate of (such shape that a channel can be used vboth for guiding the film past registering windows and for guiding a mechanismoperable from outside said channel for advancing said tape by engaging in the perforations of said tape a claw iiexibly mounted in xsaidA mechanism, means whereby the motion within the channel of said mechanism is limited so the tape will be carried to a suitable position for registry with said windows, said-Windows containing a flexible translucent material sprung into place from the front and extending laterally beyond the margins of the opening through which it is sprung, means for locating it laterally, a ledge supporting it from the rear atvthe top and bottom and two rails supporting it at the sides, said rails being so positioned that their outside `faces fall slightly within the vertical margin of the said opening.

11. A lm viewing device for viewing in the still state a series of pictures or images on a perforated film tape, the device having a casing forming binocular eye tubes, and a channel of such shape and size that it can be used both for guiding the lm past registering Ywindows and for guiding a mechanism operable from outside y said channel for advancing said'tape by engaging in the perforations of said tape a claw flexibly mounted in said mechanism, said claw having an integrally formed extension arm which by engagement with a camming surface in the front plate of the iilm guiding channel is forced out of engagement with said tape at one of the limiting positions of said lm advancing mechanism, and means whereby the motion within the channel of said mechanism is limited so that the tape will be carried to a suitable position for registry with the windows.

GIFFORD M. MAST. 

